Isolated the build directory
Isolated the build directory

The build directory was whatever path the qemudir had. To adjust for
allowing external mounts to be used such as NFS have made it so that the
script will use the qemudir to create an internal copy where the build
will happen so that files in the qemudir will not be affected. The
artifacts for the image will be found in ${WORKSPACE}/arm-softmmu.

Change-Id: I21cfc8c5a7817de0b8641bb4d4f0b635904dd1bc
Signed-off-by: Alanny Lopez <1a0708d0a8bc975c5c0d676d544b3b68a25ff13b@ibm.com>

openbmc/openbmc-build-scripts,openbmc/openbmc-build-scripts